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RAND_bytes(3)                                      OpenSSL                                     RAND_bytes(3)



NAME
       RAND_bytes, RAND_pseudo_bytes - generate random data

SYNOPSIS
        #include <openssl/rand.h>

        int RAND_bytes(unsigned char *buf, int num);

        int RAND_pseudo_bytes(unsigned char *buf, int num);

DESCRIPTION
       RAND_bytes() puts num cryptographically strong pseudo-random bytes into buf. An error occurs if the
       PRNG has not been seeded with enough randomness to ensure an unpredictable byte sequence.

       RAND_pseudo_bytes() puts num pseudo-random bytes into buf.  Pseudo-random byte sequences generated by
       RAND_pseudo_bytes() will be unique if they are of sufficient length, but are not necessarily
       unpredictable. They can be used for non-cryptographic purposes and for certain purposes in
       cryptographic protocols, but usually not for key generation etc.

RETURN VALUES
       RAND_bytes() returns 1 on success, 0 otherwise. The error code can be obtained by ERR_get_error(3).
       RAND_pseudo_bytes() returns 1 if the bytes generated are cryptographically strong, 0 otherwise. Both
       functions return -1 if they are not supported by the current RAND method.

SEE ALSO
       rand(3), ERR_get_error(3), RAND_add(3)

HISTORY
       RAND_bytes() is available in all versions of SSLeay and OpenSSL.  It has a return value since OpenSSL
       0.9.5. RAND_pseudo_bytes() was added in OpenSSL 0.9.5.



0.9.7l                                           2002-09-25                                    RAND_bytes(3)